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Diffstat (limited to 'protocol/scaler.xml')
-rw-r--r-- | protocol/scaler.xml | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/protocol/scaler.xml b/protocol/scaler.xml new file mode 100644 index 00000000..dfe44b87 --- /dev/null +++ b/protocol/scaler.xml @@ -0,0 +1,156 @@ +<?xml version="1.0" encoding="UTF-8"?> +<protocol name="scaler"> + + <copyright> + Copyright © 2013 Collabora, Ltd. + + Permission to use, copy, modify, distribute, and sell this + software and its documentation for any purpose is hereby granted + without fee, provided that the above copyright notice appear in + all copies and that both that copyright notice and this permission + notice appear in supporting documentation, and that the name of + the copyright holders not be used in advertising or publicity + pertaining to distribution of the software without specific, + written prior permission. The copyright holders make no + representations about the suitability of this software for any + purpose. It is provided "as is" without express or implied + warranty. + + THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS + SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND + FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY + SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN + AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, + ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF + THIS SOFTWARE. + </copyright> + + <interface name="wl_scaler" version="1"> + <description summary="surface cropping and scaling"> + The global interface exposing surface cropping and scaling + capabilities is used to instantiate an interface extension for a + wl_surface object. This extended interface will then allow + cropping and scaling the surface contents, effectively + disconnecting the direct relationship between the buffer and the + surface size. + </description> + + <request name="destroy" type="destructor"> + <description summary="unbind from the cropping and scaling interface"> + Informs the server that the client will not be using this + protocol object anymore. This does not affect any other objects, + wl_viewport objects included. + </description> + </request> + + <enum name="error"> + <entry name="viewport_exists" value="0" + summary="the surface already has a viewport object associated"/> + </enum> + + <request name="get_viewport"> + <description summary="extend surface interface for crop and scale"> + Instantiate an interface extension for the given wl_surface to + crop and scale its content. If the given wl_surface already has + a wl_viewport object associated, the viewport_exists + protocol error is raised. + </description> + + <arg name="id" type="new_id" interface="wl_viewport" + summary="the new viewport interface id"/> + <arg name="surface" type="object" interface="wl_surface" + summary="the surface"/> + </request> + </interface> + + <interface name="wl_viewport" version="1"> + <description summary="crop and scale interface to a wl_surface"> + An additional interface to a wl_surface object, which allows the + client to specify the cropping and scaling of the surface + contents. + + This interface allows to define the source rectangle (src_x, + src_y, src_width, src_height) from where to take the wl_buffer + contents, and scale that to destination size (dst_width, + dst_height). This state is double-buffered, and is applied on the + next wl_surface.commit. + + Before the first set request, the wl_surface still behaves as if + there was no crop and scale state. That is, no scaling is applied, + and the surface size is as defined in wl_surface.attach. + + The crop and scale state causes the surface size to become + dst_width, dst_height. This overrides whatever the attached + wl_buffer size is, unless the wl_buffer is NULL. If the wl_buffer is + NULL, the surface has no content and therefore no size. + + The coordinate transformations from buffer pixel coordinates up to + the surface-local coordinates happen in the following order: + 1. buffer_transform (wl_surface.set_buffer_transform) + 2. buffer_scale (wl_surface.set_buffer_scale) + 3. crop and scale (wl_viewport.set) + This means, that the source rectangle coordinates of crop and scale + are given in the coordinates after the buffer transform and scale, + i.e. in the coordinates that would be the surface-local coordinates + if the crop and scale was not applied. + + If the source rectangle is partially or completely outside of the + wl_buffer, then the surface contents are undefined (not void), and + the surface size is still dst_width, dst_height. + + The x, y arguments of wl_surface.attach are applied as normal to + the surface. They indicate how many pixels to remove from the + surface size from the left and the top. In other words, they are + still in the surface-local coordinate system, just like dst_width + and dst_height are. + + If the wl_surface associated with the wl_viewport is destroyed, + the wl_viewport object becomes inert. + + If the wl_viewport object is destroyed, the crop and scale + state is removed from the wl_surface. The change will be applied + on the next wl_surface.commit. + </description> + + <request name="destroy" type="destructor"> + <description summary="remove scaling and cropping from the surface"> + The associated wl_surface's crop and scale state is removed. + The change is applied on the next wl_surface.commit. + </description> + </request> + + <enum name="error"> + <entry name="bad_value" value="0" + summary="negative values in width or height"/> + </enum> + + <request name="set"> + <description summary="set the crop and scale state"> + Set the crop and scale state of the associated wl_surface. See + wl_viewport for the description, and relation to the wl_buffer + size. + + The bad_value protocol error is raised if src_width or + src_height is negative, or if dst_width or dst_height is not + positive. + + The crop and scale state is double-buffered state, and will be + applied on the next wl_surface.commit. + + Arguments dst_x and dst_y do not exist here, use the x and y + arguments to wl_surface.attach. The x, y, dst_width, and dst_height + define the surface-local coordinate system irrespective of the + attached wl_buffer size. + </description> + + <arg name="src_x" type="fixed" summary="source rectangle x"/> + <arg name="src_y" type="fixed" summary="source rectangle y"/> + <arg name="src_width" type="fixed" summary="source rectangle width"/> + <arg name="src_height" type="fixed" summary="source rectangle height"/> + <arg name="dst_width" type="int" summary="surface width"/> + <arg name="dst_height" type="int" summary="surface height"/> + </request> + + </interface> +</protocol> |